Machine for grinding lenses.



No. 781,712. PATENTBD FEB. 7, 1905. L. W. BUGBEB.

MACHINE FOR GRINDING LENSES.

APPLIOATION FILED JUNE 19, 1902.

22 7 2SHEETS-SHEET1.

M 65 In Veiibr No. 781,712. PATENTED FEB. 7, 1905. L. W. BUGBBE.

MACHINE FOR GRINDING LENSES.

APPLICATION FILED JUNE 19, 1902.

2 SHEETS-SHEET 2.

UNITED STATES Patented February '7, 1905.

PATENT EEicE.

LUCIAN W. BUGBEE, OF TILTON, NEW HAMPSHIRE, ASSlG-NOR l() EMMA J.BUGBEE, OF SOUTHBRIDGE, MASSAUHUSETTS.

MACHINE FOR GRINDING LENSES.

SPECIFICATION forming part of Letters Patent No. 781,712, dated February'7, 1905.

Application filed June 19, 1902. Serial No. 112,301.

To a, whom/ it nL/ty concern.-

Be it known that l, LUCIAN \V. BUGBEE, a citizen of the United States.residing at Tilton, in the county of Belknap and State of 5 NewHampshire, have invented a new and useful lmproven'ient in Machines forGrinding Lenses. of which the following is a specification accompaniedby drawings forming a part of the same. in which--- Figure 1 representsa front view of a ma chine for grinding lenses embodying my invention.Fig. 2 is a central vertical sectional view of the oscillating yoke forimparting a reciprocating motion to the lens-holder. Fig. 5 3 is acentral vertical sectional view through a portion of the actuatingmechanism for moving the lens-holder. Fig. i is a perspective view ofthe lens-holder. Fig. 5 is a top view of the gear and crank-plate forimparting a 20 compound movement to the lens-holder. Fig.

6 is a top view of the gear containing an eccentric groove for varyingthe throw ofa crankplate carried by the gear shown in Fig. 5. Fig. 7 isa perspective view of the adjustable 5 block 20. Fig. 8 is a detachedview of a por tion of tension device for imparting a down ward pressureto the lens-holder, and Fig. 9 represents a modified form ofgrinding-surface.

Similar reference letters and ligures refer to similar parts in thedifferent views.

My present invention relates to a machine for grinding lenses; and ithas for its object to provide a simple and eflicient mechanism 35 forimparting the desired movements to the lens-holder and also to providemeans for the requisite adjustments by which the movements of thelens-holder may be varied; and it consists in the construction andarrangement of 4 parts, as hereinafter described.

Referring to the accompanying drawings, 1 denotes a stand or frameworkcomprising a table 2, upon which are mounted the vertical stands 3,provided at their upper ends with 45 bearings at for a shaft 5, capableof a rocking and also of a longitudinally-slidingmovement within itsbearings. The rocking and longitudinally-sliding movement of the shaftis accomplished by means of a crank-plate 6, carried upon the upper sideof a rotating gear 7 and provided with a series of semispherical sockets8 to receive the spherical end f) of a sliding spindle 10, held in asleeve 11, carried upon the shaft and at right angles thereto. saidsleeve ll being attached to the shaft by means of the hollow hubs l2 12.which receive ends of the shaft 5 and are fastened thereto by means ofthe pins 13. The spindle i0 is capable of a sliding movement in thesleeve 11 and is pressed downward into engagement with the crank-plate 6by means of a spiral spring 1%, which bears against the upper end of thespindle and also against a vasher15 on the end of an :uljusting-scrmv16. provided with a hand-wheel l7. by which the tension of the spring isadjusted. The axis of the spindle 10 intersects the axis of the shaft 5,the position of the shaft relatively to the spindle 10 being shown bythe broken lines 5. Fig. 3. As the crank-plate 6 is rotated by therotation of the gear 7 the lower or spherical end 9 of the spindle 10 iscarried in a circular path around the axis of the gear 7. therebyimparting both a rocking motion and a longitudinally-sliding motion tothe shaft The shaft 5 carries a yoke 18. provided with ways 19 for asliding block .20. which is vertically adjusted in the ways 19 by meansof an adjlisting-screw 21 and halal-wheel 22. The sliding block isprovided at its lower end with a mortise or slot 23. in which is pivotedan arm A on a stud 25. The forward end of the arm 2 carries a splitbearing 26. which is clamped upon a vertical stem 28 by a clamping-bolt27. The lower end 29 of the stem 28 is round and bears upon the uppersurface of a lens-holder 30, and the stem 28 also carries a cross-bar31, provided at its opposite ends with gudgeons 32, inclosed in theslots 33 of the lugs St on the opposite holder. This prevents rotationof the lens-holder 30 around the stem 28. As the slots 33 of the lugs 34are open at the top, the stem 28 may be raised in the sleeve 26 byloosening the set-screw E27 and the lens-holder 30 released,

so that another lens-holder may be easily substituted, if desired.

. a grinding-shell or lap 39, having an upper curved surface 40, whoseshape and eurvature is determined bythe character of the lens to beground. As the shaft 5 is rocked a rocking motion is given to the yoke18 about the axis of the shaft 5, and if the block 20 be so adjustedthat the axis of the pivot is brought coincident with the axis of theshaft 5 no movement will be given to the lens-holder except that causedby the longitudinal movement of the shaft 5, which will cause thelens-holder to slide back and forth on the lap 39 in a line parallelwith the axis of the shaft 5. If, however, the block 20 be moved in theways 19, carrying the axis of the pivot 25 below the axis of the shaft5, then the rocking motion of the shaft 5 and yoke 18 will impart atraversing movement to the lens-holder back and forth across the lap 39;but as the rocking movement and the longitudinally-sliding movement ofthe shaft 5 are synchronous the compound movement of the shaft 5 willresult in a circular movement of the lens-holder over the surface of thelap.

The gear-wheel 7 is rotated by a pinion 41, carried upon the upper endof a shaft journaled in a bracket 42, said shaft carrying upon its lowerend a belt-pulley 43, which is driven by a belt connection 44 from apulley 45 to a counter-shaft 46, journaled in bearings on the frame ofthe machine and below the table 2, said counter-shaft 46 carrying tightand loose pulleys 47 48, by which the machine is driven from a main lineof shaft- Attached to the under side of the table 2 is a bracket 49,carrying a stud 50, on which is pivoted a bell-crank 51, having a handle52 on one of its arms and carrying on its opposite arm atightening-pulley. The bellcrank is rocked to carry thetightening-pulley against the belt and is held in position by aclamping-bolt 54 passing through a curved slot 55 in the bell-crank andtightening the bell-crank against the bracket 49.

The gear-wheel 7 turns loosely about a stud 56 held in the table 2, andbeneath the gear7 and d rivenby the pinion 41 is a gear 57 of the samediameter as the gear 7, but having a different number of teeth, thenumber of teethbeing usually increased or decreased by one. The gear 57is provided upon its upper surface with an eccentric slot 58, in whichslides a block 59, carrying a stud 60, the upper end of which enters thecrank-plate 6. As the two gears 7 and 57 are rotated by the pinion 41their relative position is gradually being changed,-owing to thedifference in the number of teeth, the gear 57 having a rotary movementrelatively to the gear 7, which causes the crank-plate 6 to slidebetween ways 6161 on the upper surface of the gear 7 a distance equal tothe eccentricity of the groove 58, the gear 7 being provided with a slot62 to provide for the sliding movement of the stud 60. The lower end ofthe spindle 10 when placed in any one of the semispherical sockets 8 ofthe crank-plate 6 will be carried by-the crank-plate in a circular path;but the diameter of the circular path will be constantly varying, owingto the sliding movement of the crank-plate 6 in its ways 61 61, asalready described, thereby constantly varying both the oscillatingmovement and the longitudinally-sliding movement of the shaft 5, andconsequently causing the lens-holder 29 to be moved over the surface ofthe lap 39 in a constantly-changing path. The amplitude of theoscillating and longitudinally sliding movement of the shaft 5 can alsobe varied by shifting the spindle 10 from one of the semisphericalsockets 8 to another, thereby changing the radius of the circular pathdescribed by the spindle. The back-and-forth traversingmovement of thelens-holder can also be varied, as already mentioned, by sliding theblock 20 in the ways 19 by means of the adjusting-screw 21, whichincreases or decreases the throw of the yoke.

The lens A is attached to the lens-holder in the usual manner by meansof adhesive material B, and the lap 39 may be readily exchanged forothers of difierent curvatures, and the supplemental table 35 may beentirely removed from the table 2 and other grindingsurfacessuch, forexample, as that shown at 63, provided with a stem 64 to be held in thesocket 65may be employed in lieu of the lap 39.

The arm 24 is provided with a tailpiece 66, extending on the oppositeside of the pivot 25, which is connected by a spiral spring 67 with anadjusting-screw 68, which is held in the polygonal sliding bar 69,sliding in bearings 69 supported upon the upright stands 3. The screw 68passes loosely through the sliding bar 69 and is raised and lowered by athumb-nut 70 for the purpose of varying the tension of the spring 67.The bar 69 is given a longitudinal sliding motion corresponding to thesliding movement of the shaft 5 by means of a segment 71, attached tothe yoke 18 and having its outer edge 72 concentric with the axis of theshaft 5 and inclosed between the friction-rolls 73 73, held on studs 74,projecting from the side of the sliding bar 69. As the shaft 5 is givena longitudinally-sliding movement carrying the yoke 18, a correspondinglongitudinally-sliding movement will be imparted to the square slidingbar 69, so as to maintain the adjusting-screw 68 in the same verticalplane as the tailpiece 6, which projects from the rear side of the armQ-l. The tension of the spring 67, which can be varied by adjusting thescrew 68, serves to impart a downward pressure upon thel6llH-l1(')l(l0i.29.

Having described the movement of the lensholder as resulting from thecompound motions imparted to the yoke 18, the capability of the machinein grinding lenses of different curvatures by the employment of laps ofvarying faces will be readily understood by those conversant with thisclass of machines. As the motion of the surface of the lens attached tothe lens-holder is relative to the grinding-surface of the lap, it willbe readily seen that the attachment of the lens to the moving holder 30instead of to the stationary lap 32) is determined by convenience inconstruction and operation. In some instances it may be desirable tohold the lens by the lixed instead of the moving surface. Variouschanges in the machine as shown and described may also be made withoutdeparting from the spirit of my present invention,which has for itsobject to reduce the number of operating parts, decrease the number ofadjustments required to produce any desired variation in the relativemovement of the lens and the gririding-surface, and to simplify theconstruction in machines of this class without narrowing the scope ofits operation.

hat I claim as my invention, and desire to secure by Letters Patent, is

1. In a machine for grinding lenses, the combination with agrinding-surface and a lensholder. of mechanism for producing a relativemovement between the lens holder and said grinding-surface, andcomprising a shaft capable of both a longitudinally-sliding and anoscillating motion, an actuating-crank having its axis at right anglesto the axis of said shaft, a sleeve carried by said shaft and a slidingspindle in said sleeve operatively connected with said crank, wherebythe rotation of said crank will simultaneously slide and oscillate saidshaft, substantially as described.

The combination with fixed and movable members adapted togrind a lensbetween them, of a shaft capable of an oscillating and a sliding motion,a crank having its axis at right angles to the axis of said shaft, andoperatively connected therewith to sin'iultaneously oscillate and slidesaid shaft, a yoke carried by said shaft, means for pivotally connectingsaid yoke and said movable member, substantially as described.

3. The combination with fixed and movable mom 1 ers adapted to grind alens between them, of a yoke pivotally connected with said movablemember, means for varying the axis of said pivotal connection in saidyoke, a shaft carrying said yoke, an actuating-crank having its axis atright angles to the axis of said shaft and operatively connectedtherewith to simultaneously impart a sliding and an oscillating motionto said shaft, substantially as described.

:t. The combination with the lixed and movable mcmbers in alens-grinding machine adapted to grind a lens held between them, of asimultamously-oscillating and a longitudinally-sliding shaft, means formoving said shaft, a yoke carried by said shaft and having ways radialto its axis, a block capable of sliding in ways, an arm pivotallyconnected with said block and carrying said movable member and means foradjustably holding said block in said yoke, substantially as described.

5. The combination with fixed and movable members adapted to grind alens held between them, of mechanism for imparting a resultant circularmovement to said movable member and comprising a single shaftoperatively connected with said movable member and means for impartingan oscillating and a longitudinally-sliding motion simultaneously tosaid shaft, substantially as described.

6. The combination with lixed and movable members adapted to grind alens between them, of a shaft operatively connected with said movablemember, a crank having its axis at right angles with the axis of saidshaft, means for operatively connecting said crank and said shaft,whereby a sliding and an oscillating motion is imparted to said shaft,and means for imparting a pressure between said fixed and said movablemembers, substantially as described.

7. The combination with lixed and movablemembers adapted to grind a lensheld between them, of mechanism for imparting a circular movement tosaid movable member, means for applying pressure to said lixed andmovable surfaces, and means for adjusting said pressure, substantiallyas described.

8. The combination with lixed and movable members adapted to grind alens held between them, of a shaft operatively connected with saidmovable member, means for imparting asimultaneous, oscillating andlongitudinallysliding motion to said shaft and means for automaticallyvarying said motions, whereby the path of said movable member isconstantly varied, substantially as described.

S). The combination with lixed and movable members adapted to grind alens between them, of a shaft operatively connectml with said movablemember, a crank having its axis at right angles with said shaft andoperatively connected therewith, whereby a sliding and an oscillatingmotion is imparted to said shaft, and means for varying the throw ofsaid crank, substantially as described.

10. The combination with lixed and movable members adapted to grind alens held between them, of mechanism for imparting a compound movcmentto said. movable member, whereby said member is moved in a curved path,means for automatically imparting a constant variation to the movementof said ITO &

movable member, whereby it is made to continually vary its path,substantially as described.

11. The combination with fixed and movable members adapted to grind alens held between them, of a simultaneously-oscillating andlongitudinally reciprocating shaft operatively connected with saidmovable member, means for imparting said motions to the shaft andcomprising a rotating gear carrying a crankplate capable of slidingradially on said gear, a second gear provided with an eccentric groove,a block running in said groove and operatively connected with saidsliding crankplate and a pinion engaging said gears in common, saidgears having a different number of teeth, whereby said gears are drivenat slightly-varying speeds, substantially as described.

12. The combination with fixed and movable members adapted to grind alens held between them, of a shaft having a simultaneously-oscillatingand a longitudinallysliding motion, means for actuating said shaft, ayoke carried by said shaft and provided with radial ways, a block heldin said ways, an adjusting-screw by which said block is adjustably heldin said ways, an arm pivotally held in said block and operativelyconnected with said movable member, substantially as described.

13. The combination with a fixed lap havinga grinding-surface, of alens-holder arranged to move over said lap, a vertical stem pivotallyconnected to said lens-holder, an arm adjust-ably attached to said stemand an oscillating and simultaneously-reciprocating yoke pivotallyconnected to said arm, substantially as described.

let. The combination with the fiXed and movable grinding members, of alens-grinding machine, of an oscillating and simultaneouslyreciprocatingyoke, an arm pivotally held in said yoke and operatively connected withsaid movable member, a rod held in fixed bearings and capable of slidingtherein, means for imparting a sliding movement to said rodcorresponding with the reciprocating motion of said yoke and a spiralspring connecting said rod and said arm, whereby the tension of thespring is made to impart a pressure to the grinding members,substantially as described.

15. The combination with afixed lap provided with a grinding-surface, ofa movable lens-holder consisting of a plate having slot-ted lugs, saidslotted lugs being open at the top, a vertical stem with its endarranged to bear on said plate, a cross-bar held in said stem havinggudgeons at its ends sliding vertically in said slotted lugs, wherebysaid plate is capable of a slight rocking motion, substantially asdescribed.

16. In a lens-grinder comprising a shaft having asimultaneously-oscillating and longitudinally-sliding motion, whereby aresultant curved movement is imparted to the movable grinding member,the combination with said shaft, of an actuating mechanism con sistingof a sleeve carried by said shaft and at right angles thereto, a slidingspindle carried by said sleeve, a rotating crank-plate engaging the endof said spindle and a pressurespring bearing against the end of saidspindle to hold it against said crank-plate, substantially as described.

17. The combination with the oscillating and reciprocating shaft 5, of asleeve carried by said shaft, a spindle held in said sleeve, a

rotating crank-plate provided with a series of sockets to receive theend of said spindle and a yielding spring bearing against said spindleto hold it in engagement with said crank-plate, substantially asdescribed.

Dated. this 10th day of June, 1902.

LUCIAN W. BUGBEE.

lVitnesses:

RUFUS B. FOWLER, M. M. SOHUERMANN.

